Localized, multivoxel 1H spectroscopy (MRS) of in vivo human brain is currently of great interest. To increase the efficiency of commonly used CSI techniques we develop 3D coverage of the volume-of-interest (VOI), which excites and observes the spins in the entire volume every acquisition. Therefore, R(N) SNR gain per given measurement time is expected over the current method of sequential interleaving N 2D slices. 3D coverage is achieved with a hybrid of chemical shift imaging (CSI) and transverse Hadamard spectroscopic imaging (HSI) to obtain 3D, multivoxel arrays of voxels in a Siemens SP63 imager in ~25 min. CHESS water suppression was followed by outer-volume-suppression of the fat signals and selective-excitation of an axial, slab-likeVOI. The spatially-selective HSI-encoding RF pulses incorporate naturally into the PRESS double spin-echo sequence used to excite the VOI selectively. This VOI accommodates few partitions along its short axis (hence the use of HSI) and many partitions along the other long axes, hence use of CSI in the hybrid. The 3D hybrid was performed on a volunteer. A 16x16x4 localization matrix in an 8x8x4 cm PRESS VOI yielded 1 ml voxels. The MRS took 25 min. and the entire session 1 hour. For comparison, a 27 min., 4 slice interleaved MRS was performed immediately afterwards without moving the volunteer or changing the imager settings. Spectra from the slice overlapping showed that (as expected) the SNR is ~twofold better than the spectra from interleaves slices for each of the 1H spectral lines. This is a result of the entire examination time available to all the slices in the hybrid, versus only N-1 of it for the interleaved.